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At least 19 recordsLinked to original sources
PubMed1978

The pineal-paraphyseal complex of sea turtles. I. Light microscopic description.

The pineal-paraphyseal complex of sea turtles is an impressively large structure which projects dorsally and anteriorly above the prosencephalon. The complex was examined by light microscopy in several age classes of green sea turtles (Chelonia mydas) and from juvenile loggerhead turtles (Caretta caretta). The paraphysis is extensively fused to the distal portion of the pineal body, suggesting an interrelated function for these two tissues. No duct or canal was observed connecting the pineal lumen to the third ventricle. Two pineal cell types are described which appear to correspond to the neuroglial supportive cells and the secretory rudimentary photoreceptor cells of other amniotic vertebrates. A possible luminal secretion in the form of apical protrusions is produced by the latter cell type. No typical photoreceptive outer segments were observed.

Animals↗
PubMed1977

Quantitative requirements of the hatchling green sea turtle for lysine, tryptophan, and methionine.

The quantitative requirement for the amino acids lysine, tryptophan, and methionine was determined for the hatchling green sea turtle (Chelonia mydas). Hatchling green sea turtles were fed synthetic diets of purified substances with the composition of the diet varying in the amount of lysine, tryptophan or methionine present. The lysine requirement was found to be 4.8% of the crude protein (N X 6.25) or 1.7% of the dry diet. The tryptophan requirement was found to be 0.63% of the crude protein or 0.22% of the dry diet. The methionine requirement, in the presence of adequate cystine (3.1% of the crude protein), was found to be 1.5% of the crude protein or 0.49% of the dry diet.

Animals↗
PubMed1979

Mycotic pneumonia in mariculture-reared green sea turtles.

Microbiologic examination of 29 juvenile green sea turtles with a buoyancy abnormality revealed pulmonary infection with Sporotrichium sp, Cladosporium sp, and Paecilomyces sp. Histologic examination of the lungs revealed granulomatous lesions containing branching septate hyphae. The diagnosis was mycotic pneumonia.

Animals↗
PubMed2026

Genomic characterization of novel human-associated CTX-M-15-producing Serratia nevei ST625 lineage infecting a vulnerable loggerhead sea turtle.

BACKGROUND: Serratia nevei is a newly classified and opportunistic bacterial species belonging to the Serratia marcescens complex (SMC). Genomic data from this species is highly relevant for public health and epidemiological tracking. OBJECTIVE: To report the first identification and genomic characterization of extended-spectrum β-lactamase (CTX-M-15)-producing S. nevei sequence type (ST) ST625 lineage infecting a vulnerable loggerhead sea turtle. METHODS: Strain BP02 was recovered from the coelomic cavity of a loggerhead sea turtle (Caretta caretta) admitted to a rehabilitation center in southeastern Brazil. MALDI-TOF MS was initially used for species identification and was further confirmed by whole-genome sequencing on the Illumina HiSeq platform, followed by ANI, dDDH, multilocus sequence typing, resistome, plasmidome, virulome, and SNP-based phylogenomic analyses. RESULTS: Strain BP02 exhibited a multidrug-resistant profile, including resistance to third- and fourth-generation cephalosporins. Genomic analyses identified BP02 as S. nevei ST625 carrying blaCTX-M-15 within the ISEcp1-blaCTX-M-15-wbuC-ΔTn2 genetic environment, in addition to multiple AMR determinants and the IncC plasmid replicon. Phylogenomic analysis demonstrated close relatedness between BP02 and human clinical ST625 strains, previously reported in São Paulo, Brazil, including a urine-derived strain isolated in 2019, differing by only 27 SNPs. Notably, all publicly available ST625 genomes were associated with human clinical sources and displayed multidrug resistance genotypes. CONCLUSION: This study expands the current knowledge regarding the ecology and genomic features of S. nevei, demonstrating the emergence of a human multidrug-resistant clone in marine wildlife. Our findings reinforce the importance of monitoring clinically relevant SMC members across distinct ecological niches within a One Health perspective.

ESBL↗
PubMed1975

A herpesvirus-type agent associated with skin lesions of green sea turtles in aquaculture.

Nine successive groups of green sea turtles (Chelonia mydas) were observed in aquaculture during the posthatchling period. During the first 6 months of growth, each group underwent an epizootic of skin lesions, named gray-patch disease. Two types of skin lesions are associated with gray-patch disease: papules and, more characteristically, spreading gray patches which appear 7 to 8 weeks after hatching. In both types of lesions, intranuclear inclusions are found in keratinocytes in the malpighian layer of the epidermis. Electron microscopic examination of scrapings from lesions and biopsies revealed many viral particles, with features characteristic of the herpesvirus group. Transmission of gray-patch disease is possible with bacteria-free preparations of viral particles.

Animals↗
PubMed1978

Caryospora cheloniae sp. n.: a coccidial pathogen of mariculture-reared green sea turtles (Chelonia mydas mydas).

Caryospora cheloniae sp. n. is described from mariculture-reared green sea turtles (Chelonia m. mydas). The sporulated oocyst has a thin, transparent, single-layered wall which often ruptures, leaving a naked sporulated sporocyst. Oocysts measured 33.8 to 40.1 micrometer by 11.0 to 14.6 micrometer (mean 37.4 by 12.8 micrometer). Greatest concentrations of developmental stages of C. cheloniae were found in the hindgut. Transverse binary fission was observed in dividing tissue stages. Pathologic alterations were most pronounced in the posterior third of the intestines (hindgut). The hindgut lumen was greatly dilated and filled with blood, oocysts and tissue debris. The hindgut wall was thinner than normal and the mucosal folds had sloughed into the intestinal lumen. Free blood escaped from the blood vessels of the tunica propria into the intestinal lumen. Epithelial hyperplasia was pronounced at the margins of denuded mucosal areas. Numerous inflammatory cells infiltrated the infected mucosal surface.

Animals↗
PubMed1979

Radioimmunoassay of plasma progesterone, testosterone, total estrogen and immunoreactive gonadotropin in the nesting and non-nesting green sea turtle, Chelonia mydas (L.).

Plasma progesterone, testosterone, total estrogens and immunoreactive gonadotropin were measured in nesting and non-nesting sea turtles, Chelonia mydas. Progesterone and gonadotropin concentrations were significantly higher in nesting than in non-nesting turtles, testosterone was not significantly different in either group and total estrogens appeared to be slightly in the nesting group.

Animals↗
PubMed1977

Effect of water temperature on a herpesvirus infection of sea turtles.

The role of water temperature in the induction and maintenance of a dermal herpesvirus infection (gray-patch disease) of young, green sea turtles (Chelonia mydas) was studied under carefully controlled experimental conditions, in which the influence of other recognized stress factors was negligible. A nimals that were subjected to a gradual temperature increase from 25 to 30 degrees C, with subsequent maintenance at 30 degrees C, and those that were abruptly shifted from water at 25 degrees C to water at 30 degrees C showed a significantly shorter period before the onset of clinical signs and an increase in the severity of the lesions when compared with control animals. Animals that were subjected to a gradual increase in water temperature from 25 to 30 degrees C and a subsequent decrease to 25 degrees C, where they were maintained, had a period before onset of clinical signs and severity closer to that of control animals. Our findings indicate that both the induction of clinical gray-patch disease and the severity of the lesions are affected by water temperature and suggest that one possible means of control of this herpesvirus infection under intensive aquaculture conditions might be water temperature manipulation.

Animals↗
PubMed1979

Ventilatory response to inspired CO2 in the sea turtle: effects of body size and temperature.

The ventilatory response of green turtles (Chelonia mydas) to inspired CO2 was tested. Both immature (0.9--1.35 kg) and adult (59--130 kg) animals responded with increased ventilation (VE) that was primarily (immature) or exclusively (adult) due to increased respiratory frequency. The VE of the immature turtles while breathing air increased with temperatures between 15 and 35 degrees C with a Q10 of 1.95, but the peak VE of these turtles while breathing 4.5% CO2 in air was not significantly different at 15, 25 or 35 degrees C. VE increased irregularly with time throughout an hour of CO2 breathing in both groups, although several of the adult animals exhibited a first-breath response to CO2 and all animals increased VE within 5 min after the onset of CO2 breathing. The VE of an immature turtle at 35 degrees C increased with graded increases in CO2 up to 6%, but at 15 and 25 degrees C VE increased only up to 4.5% and decreased with 6% CO2. The results are discussed in terms of possible receptor mechanisms involved.

Aging↗
PubMed2026

Highly Contiguous Is Not Chromosomally Accurate: Integrated Cytogenetic and Genomic Mapping in Two Turtle Genome.

High-quality genome assemblies are essential for robust research across biological and medical fields. Assembly errors can have far-reaching consequences for downstream analyses, including gene annotation and the inference of synteny. In contrast to the rapid growth of genomic data volume, there is a notable lag in the integration of chromosome-level assemblies with cytogenetic data. We conducted the first direct genome-to-genome comparison, integrating comparative chromosome painting, the alignment of chromosome-specific probes to available genome assemblies, and synteny-based comparison of independent chromosome-level assemblies of the loggerhead sea turtle (Caretta caretta, 2n = 56) and the red-eared slider (Trachemys scripta elegans, 2n = 50). Using two independent sets of flow-sorted chromosome-specific probes in cross-species hybridizations, together with the sequencing and mapping of chromosome-derived DNA libraries, we assigned assembled scaffolds to all physical chromosomes of both species. In C. caretta, chromosomal assignments and genome-wide synteny were fully consistent with the published assembly, except for the reduced sizes of two microchromosome scaffolds, which we attribute to under-representation of repetitive DNA. In contrast, in T. s. elegans, cytogenetic validation of the assemblies revealed a false rearrangement compared to a missed one. Our results show that even highly contiguous vertebrate genome assemblies can misrepresent chromosome structure. When cytogenetic analyses reveal such inaccuracies, updated reference genomes should be generated for widely studied species to enable accurate inference of karyotype evolution and downstream comparative genomic analyses.

FISH↗
PubMed1978

Phylogenetic distribution of aromatase and other androgen-converting enzymes in the central nervous system.

Metabolism of [3H]androstenedione was studied in brain tissue homogenates of opossum, bird, snake, sea turtle, urodele amphibian, teleost, shark, skate, hagfish, and lobster. Estrone, 17 beta-estradiol, or 17 alpha-estradiol was formed by central neural tissues of all species, with the exception of the opossum, hagfish, and lobster. Aromatase activity was concentrated in the forebrain, although some estrogen was synthesized by mid- or hindbrain homogenates of two lower vertebrates (teleost and skate) and the newly hatched chick. 5 alpha-Androstanedione (5 alpha-androstane-3,17-dione) or 5 alpha-dihydrotestosterone were products of metabolism in several nonmammalian vertebrates and in the invertebrate central nervous system also. 5 alpha-Reductase was found in all major brain divisions. These and previously reported comparative studies indicate that the ability to aromatize and otherwise transform androgen substrates is a primitive characteristic of the brain that has been widely conserved phylogenetically.

Androstenedione↗
PubMed1979

Seaward orientation of hatchling turtles: turning systems in the optic tectum.

This paper reports studies on the mechanisms underlying seaward orientation in hatchling turtles. The particular aim was to investigate whether activity in different regions of the retina and associated tectal areas, as assessed by some comparator mechanism, results in turning in different directions. Hatchling green turtles (Chelonia mydas) were tested for sea-finding ability in a natural situation on the beach following lesions of the optic tectum. Asymmetrical bilateral lesions resulted in a number of turtles making circles in the direction of the tectum with the posterior lesion and in other turtles deviated in this direction. Bilaterally lesioned turtles were also slower and less consistent in their sea-finding behaviour. No major disruptions of sea finding were detected in animals with unilateral tectal lesions. By suspending lights in the nasal visual field of unilaterally blindfolded green and leatherback turtles (Dermochelys coriacea) it was possible to produce circling in the direction of the covered eye; in contrast, with the light suspended in the temporal field, turning was always in the direction of the uncovered eye. The results are consistent with the view that sea finding depends on a complex phototropotactic system with stimulation in different parts of a single retina being associated with turning in opposite directions.

Animals↗